BMI Calculator

Assessing a patient should include the evaluation of body mass index, or BMI. BMI is calculated by multiplying the individual’s weight in pounds by 703, and then dividing by the height, in inches, squared. This approximates BMI in kilograms per meter squared (kg/m2). There is evidence to support the use of BMI in risk assessment since it provides a more accurate measure of total body fat compared with the assessment of body weight alone, though the judgment of a healthcare provider should be used when evaluating patients with above-average musculature. This is because BMI can overestimate the degree of fatness in these patients.

The calculator and table below provide a BMI and the corresponding BMI weight status category. Use this calculator for adults 20 years and older.

BMI Calculator

  1. inches
  2. pounds

Body Mass Index (BMI) 0

BMIWeight Status
Below 18.5Underweight
30.0 and AboveObese


For children and teens, two to 19 years old, use the BMI Calculator for Children and Teens.